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Trillium ovatum

Pacific trillium, trillium, western trillium, western wake-robin, western white trillium, white or western trillium, white trillium

Photo is of parent taxon

Pacific trillium, western trillium, western wake-robin, western white trillium


semierect to horizontal, short, stout, praemorse.


1–2, round, 2–5 dm, ± slender, glabrous.


sessile, subsessile, or short-petiolate;

blade medium green, sometimes blotched and mottled, main veins prominent, ovate-rhombic, 7–12 × 5–20 cm, continuing to expand during anthesis, base rounded, apex acuminate.



erect or nodding, odorless;

sepals spreading to horizontal, green, lanceolate to oblong-lanceolate, 15–50 × 6–20 mm, margins entire, apex acute;

petals erect-ascending, usually wide-spreading from base, exposing entire pistil, white or with pink or blush markings, lacking V-shaped markings, fading to rosy pink, purple, or dark red, veins not deeply engraved, ± linear to widely obovate, 1.5–7 ×1–4 cm, widest at or above middle, thin-textured, margins flat to undulate, apex acuminate;

stamens prominent, slightly recurved-spreading to straight, 10–18 mm;

filaments white, shorter than anthers, slender;

anthers yellow, 4–16 mm, slender, dehiscence latrorse-introrse;

ovary green or white, ovoid, 6-angled, 5–12 mm, attachment ± 3/4 ovary width;

stigmas recurved, barely connate basally, greenish white or white, linear, not lobed adaxially, 6–10 mm, uniformly thin;

pedicel erect to leaning, 2–6 cm.


petals lanceolate to obovate, 1.5–7 × 1–4 cm;

pedicel erect.


baccate, green or white, ± odorless, broadly ovoid, obscurely winged, 1.2–2.8 × 0.7–1.9 cm, pulpy-moist.


= 10.

Trillium ovatum

Trillium ovatum var. ovatum

Phenology Flowering late winter–spring (late Feb–Apr).
Habitat Coniferous and mixed coniferous-deciduous forests, alder thickets, shrubby areas
Elevation 60–1600 m (200–5200 ft)
from USDA
w North America
[WildflowerSearch map]
[BONAP county map]
from FNA
[BONAP county map]

Varieties 2 (2 in the flora).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Two forms of Trillium ovatum should be noted. Forma hibbersonii T. M. C. Taylor & Szczawinski, a dwarf, grows on sea cliffs on Vancouver Island, British Columbia. Plants range from 3 to 10 cm tall, with all parts proportionally diminished, and petals opening clear pink, fading to white. T. M. C. Taylor and A. F. Szczawinski (1974) stated that this form occurs occasionally throughout the range of the species. Forma maculosum Case & R. B. Case, with bracts blotched or spotted with dark maroon or maroon-green markings on the adaxial (but not the abaxial) surface in the manner of the sessile trilliums, and with moderate-sized flowers, is locally abundant in Mendocino County near Gualala. This is the only reported instance of maculate leaves in a pedicellate Trillium.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

1. Bracts sessile; petals lanceolate to obovate, 1.5–7 × 1–4 cm
var. ovatum
1. Bracts distinctly short-petiolate; petals linear to linear-lanceolate, 0.5–2.4 × 0.2–0.6 cm
var. oettingeri
Source FNA vol. 26, p. 100. FNA vol. 26.
Parent taxa Liliaceae > Trillium > subg. Trillium Liliaceae > Trillium > subg. Trillium > Trillium ovatum
Sibling taxa
T. albidum, T. angustipetalum, T. catesbaei, T. cernuum, T. chloropetalum, T. cuneatum, T. decipiens, T. decumbens, T. discolor, T. erectum, T. flexipes, T. foetidissimum, T. gracile, T. grandiflorum, T. kurabayashii, T. lancifolium, T. ludovicianum, T. luteum, T. maculatum, T. nivale, T. parviflorum, T. persistens, T. petiolatum, T. pusillum, T. recurvatum, T. reliquum, T. rivale, T. rugelii, T. sessile, T. simile, T. stamineum, T. sulcatum, T. underwoodii, T. undulatum, T. vaseyi, T. viride, T. viridescens
T. ovatum var. oettingeri
Subordinate taxa
T. ovatum var. oettingeri, T. ovatum var. ovatum
Synonyms T. ovatum var. stenosepalum
Name authority Pursh: Fl. Amer. Sept. 1: 245. (1814) unknown
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